Ultrasonic plastic welder ensures reliability of food safety device

Food-borne illness is no laughing matter. In 1985, a listeriosis outbreak in Southern California killed as many as 40 people. The outbreak was eventually traced to a Mexican-style soft cheese contaminated with the bacterium Listeria monocytogenes. To prevent such outbreaks, food and drug manufacturers take great pains to test their products frequently for any sign of contamination. The equipment they use must meet rigorous requirements set forth by the Association of Analytical Communities International (AOAC), a nonprofit organization that develops standards for laboratory devices. Eventually, Invisible Sentinel met with Branson Ultrasonics Corp. to discuss the feasibility and benefits of ultrasonically welding the housing. Branson recommended its 2000X-d assembly system for the task. Through controlled experiments, engineers from both companies determined the optimum force, triggers and distance settings to maximize system energy and efficiency in the welding process. Separately, Branson engineers defined the horn and nest parameters using finite element analysis.